System for controlling electroresponsive means



June 8, 1965 R. J. BYRNES ETAL 3,188,529

SYSTEM FOR CONTROLLING ELECTRORESPONSIVE MEANS Filed July 27, 1961 United States Patent 3,188,529 SYSTEM FOR CUNTROLLIWG ELECTRU- RESPGNSIVE MEANS Richard J. Byrnes, West Allis, and Carl Ii. Weiss, Mile an- This invention relates to systems for controlling electroresponsive means and more particularly to systems responsive to application and removal of input signals for controlling memory type electroresponsive means between a plurality of operating positions.

While not limited thereto, the invention is especially applicable to control systems for operating electroresponsive switches or the like which require a first energization to operate the switch to a first operating position and require a second energization to operate the switch to a second operating position or to restore the switch to its normal position.

An object of the invention is to provide improved systems for operating electroresponsive means.

A more specific object of the invention is to provide an improved control system for operating a memory type load device having a plurality of operating conditions and which remainsin any condition it is in in the event of power failure. 7

Another specific object of the invention is to provide an improved control system for operating a memory type load device having a plurality of operating conditions and which remains in any condition it is in in the event of interruption and reestablishment of its electrical power.

Another specific object of the invention is to provide improved means which electroresponsively assumes a first operating condition when an input signal is applied thereto and which electroresponsively assumes a second, different operating condition when the input signal is removed whereby said means will return, upon reestablishment of power, to any condition that it was in when the power was interrupted.

According to the invention, there is provided a memory type electroresponsive system. The system comprises two transistors for controlling energization of the operating coil and resetting coil, respectively, of an electroresponsive load, such as a two coil relay of the latching type or the like. The system is so arranged that connection of power thereto causes the first transistor to be biased to non-conduction thereby permitting the resetting coil connected across the first transistor to energize. Energization of the resetting coil causes the second transistor to be biased to conduction and to shunt the operating coil connected thereacross. Application of an input signal biases the first transistor to conduction to shunt the resetting coil. This shunting of the resetting coil causes the second transistor to be biased to non-conduction thereby permitting the operating coil to energize and either to close a normally open switch or to open a normally closed switch. Removal or termination of the input sig nal causes the system to reassume its normal condition, that is, the first transistor biased to non-conduction and the resetting coil energized and the second transistor biased to conduction and shunting the operating coil to denergize the latter. In the event of power interruption when the system is in its normal condition, the resetting coil deenergizes without effect and reenergizes when the power is reapplied. In the event of power interruption when the operating coil is energized, the operating coil denergizes and when the power is reapplied the input signal also returns to cause reenergization of the operating coil. The operating coil will remain energized as long as "ice an input signal is applied. When the input signal is removed, the resetting coil will remain energized as long as an input signal is not applied. As a result, when power is reestablished, the system will always return to the condition it was in when power failed.

These and other objects and advantages of the invention and the manner of obtaining them will best be understood by reference to the following detailed description of an embodiment of the invention taken in conjunction with the accompanying drawings, wherein:

FIGURE 1 diagrammatically shows a system for controlling electroresponsive means constructed in accordance with the invention; and

FIG. 2 is a schematic illustration of a load device usable in the system of FIG. 1.

Referring to FIG. 1, there is shown a system for controlling an electroresponsive relay of the latching type shown in FIG. 2. While for descriptive purposes, a latching relay has been shown as the load device, it is to be understood that other load devices could be employed with the system according to the invention.

The latching relay shown in FIG. 2 is provided with a first electromagnet comprising an operating coil or a closing coil CC and an armature ARM attracted thereby, when energized, against the force of a return spring RS1 to close normally open contacts C. As the armature is attracted, the free end thereof slips past a hook on a latch LA whereafter the armature is retained in its attracted position following deenergization of closing coil CC. There is also provided a second electromagnet comprising a resetting coil RC operative when energized to attract latch LA, forming an armature for the second electromagnet, against the force of return spring RS2. When latch LA is attracted by energization of resetting coil RC, it releases armature ARM to cause return spring RS1 to return the latter to its normal position and to reopen contacts C. While normally open contacts have been shown for illustrative purposes, it will be understood that normally closed contacts or combinations of normally open and normally closed contacts could be used in place thereof.

The system shown in FIG. 1 is provided with a direct current power supply source represented by a positive voltage terminal P, a negative voltage terminal N and a ground connection G which may be at zero voltage or the like. Resetting coil RC is connected in series circuit with a resistor R1 in that order between ground G and negative terminal N. Closing coil CC is connected in series circuit with a resistor R2 in that order between ground G and negative terminal N, this circuit being in parallel with the first mentioned circuit.

The system is also provided with first and second controllable semi-conductor devices such as transistors T1 and T2 of the P-N-P conductivity type or the like, each having an emitter-collector junction forming a main conduction path for the device and tan emitter-base junction forming a control conduction path therefor. The emitter-collector junction of transistor T1 is connected across reset-ting coil RC and the emitter-collector junction of transistor T2 is connected across closing co-il CC. Input means are provided comprising a pair of input terminals IN and a current limiting resistor R3 for applying negative input signals to the system. For this purpose, the negative terminal of the pair of terminals IN is connected through resistor R3 to the base of transistor T1 and the other input terminal is connected to ground G so that an input signal which is negative relative to ground potential may .be applied to the system.

The system is also provided with means responsive to control of transistor T1 for controlling transistor T2.

This means comprises a control voltage connection from the collector of transistor T1 through a current limiting resistor R4 to the base of transistor T2. The system is further provided with bias voltage means for insuring restoration of transistor T1 and T2 to their non-conducting conditions Whenever control voltages are not applied thereto. This means comprises a bias voltage connection from positive terminal P through a resistor R to the base of transistor Tll and a bias voltage connection from positive terminal P through a resistor R6 to the base of transistor T2.

Resistors R 1 and R2 serve as collector load resistors for transistors T1 and T2, respectively. Resistors R3 and R4 are provided with small values of resistance suitable for limiting the base currents of the respective transistors. values of resistance relative to the resistance of the first mentioned resistors. For example, resistor R6 is given a resistance value sufficiently high so that current flow from positive terminal P through resistors R6, R4 and R1 to negative terminal N causes a voltage of substantially ground value to be applied to the base of transistor T2. i e

' The operation of the system of FIG. 1 will now be described. Application ofunidirectional supply voltage to terminals P and N and ground connection G causes current flow from ground through resetting coil RC and resistor R1 to negative terminal N thereby to energize the resetting coil. As a result, latch LA is withdrawn from armature ARM. Positive bias voltage'is applied from terminal P through resistor R5 to the base of transistor T1 to render the base of transistor T1 positive relative to the emitter thereof and to main transistor Tll non-conductive. A negative voltage proportional to the voltage drop across resetting coil RC is applied through resistor R4 to the base of transistor-T2 to render the voltage at the base negative relative to the ground voltage Resistors R5 and R6 are provided with high at the emitter and to cause transistor T2 to conduct current from ground G through its emitter-collector junc tion and through resistor R2 to negative terminal N. As a result, transistor T2 effectively shunts closing coil CC to maintain the latter deenergized. 'The system remains in this normal condition until an input signal is applied.

In the event power tails or is interrupted, reset-ting coil RC is deenergized and transistor T2 stops conducting current; When power is reestablished, the system returns to the aforementioned normal condition, that is, resetting coil RC energized and transistor T2 conducting.

When an input signal, negative relative to groundv potential, is applied to input terminals 1N andthrough resistor R3 to the base of transistor T1 torender the base negative relative to the emitter, transistor T1 conductscurrent from ground G through its emitter-collector junction and through resistor R1 to negative terminal N. As a result, transistor T1 effectively shunts resetting coil RC to deenergize the latter and to permit restoration of latch LA to its normal position shown in FIG.

2. Since the voltage drop across the emitter-collector junction of transistor T1 when conducting is very small or negligible, the voltage at the collector of transistor T1 goes to substantially ground potential value and the base of transistor T2 goes positive relative to ground to render transistor T2 non-conducting. As a result, current flows from ground Gthrough closing coil CC and resistor R2 to negative terminal N to energize the closing coil. Armature ARM is attracted to close contacts C. The free end of armature ARM engages the inclined surface of latch LA and snapsbehind the hook on the latter whcreafter the latch maintains the contacts closed even if the operating coil is deenergized and until the resetting coil is again energized. v

In the event power fails or is interrupted which would also interrupt the input signal, transistor T1 stops contacts C remain latched in their closed position. When power is reestablished which also reestablishes the input signal, transistor T1 is again rendered conducting to shunt resetting coil RC. Also, since transistor T2 remains non-conducting under the control of its bias voltage, closing coil CC energizes. In this manner, the system restores, upon reestablishing of power, to whatever condition it was in when power was interrupted. Also, use of a memory type load device such as the latching relay or the like affords load circuit control which will not be changed due to momentary interruption of power to the control system. a

To restore the system to its normal condition, it is only necessary to remove the input signal. This has lear advantages over controls where it is necessary to apply another input signal to restore the system to its normal condition. When the input signal is interrupted, the bias voltage applied from terminal P through resistor R5 to the base of transistor T1 renders transistor T1 non conducting. Resetting coil RC energizes. A voltage negative relative to ground is again applied through resistor R4 to the base of transistor T2 to render transistor T2 conducting and to shunt closing coil CC. The

withdrawal of latch LA and deenergization of the clos ing coil permit the contacts to reopen.

While the system hereinbefore described is effectively adapted to fulfill the objects stated, it is to be understood that we do not intend to confine our invention to the particular preferred embodiment of system for ccn trolling electroresponsive means disclosed, inasmuch as it is susceptible of various modifications without departing from the scope of the appended claims; A

We claim l. in a system for controlling an electroresponsive switch device, said switch device being of the memory type and comprising an operating coil and a resetting coil and at least one switching contact which is actuated to an active position by the operating coil when it is energized and is actuated to its normal position by the resetting coil when it is energized, said switch device further comprising resilient means for maintaining said contact in said normal position when actuated thereto until said operating coilis energized and latch means a for maintaining said contact in said active position when actuated thereto until said resetting coil is energized, means for controlling said operating coil and said resetting coil comprising a unidirectional power supply,

spectively connected thereacross, means normally bias I ing said first semi-conductor device to non-conduction thereby to cause energization of said resetting coil, means responsive to energization of said resetting coil for applying a control voltage to saidsecond semi-conductor device to render the latter conducting thereby efiectively to shunt said operating coil, means for applying a small input signal to said first semi-conductor device to render the latter conducting thereby efiectively to shunt said resetting coil and to deenergize the same, and means responsive to conduction of said first semi-conductor device for biasing said second semi-conductor device to non-conduction thereby to-unshunt and cause energizetion of said operating coil.

2. The invention defined in claim ll, wherein said normal biasing means is effective responsive to termination of said input signal for biasing said first semi-con ductor device to non-conduction thereby to cause reenergization of said, resetting coil, and reenergization of said resetting coil renders said control voltage applying means effective to render said second semi-conductor device conducting thereby to shunt and deenergize said operating coil.

3. A system for controlling alternate energization of first and second electroresponsive devices by respective application and removal of an input signal voltage comprising:

an electrical power supply source;

means connecting said electroresponsive devices in parallel across said source; first and second transistors connected across said first and second electroresponsive devices respectively;

means applying bias voltages to said transistors from said source to render them non-conducting thereby to cause energization of said first electroresponsive device;

means applying the voltage drop from said first electroresponsive device to control said second transistor to render the latter conducting thereby to shunt said second electroresponsive device;

means for applying an input signal voltage to said first transistor to render the latter conducting thereby to shunt said first electroresponsive device;

and conduction of said first transistor causing the control voltage being applied to said second transistor to shift polarity under the influence of said bias voltage to render said second transistor non-conducting thereby to unshunt said second electroresponsive device.

Reterences Cited by the Examiner UNITED STATES PATENTS SAMUEL BERNSTEIN, Primary Examiner. 

1. IN A SYSTEM FOR CONTROLLING AN ELCTRORESPONSIVE SWITCH DEVICE, SAID SWITCH DEVICE BEING OF THE MEMORY TYPE AND COMPRISING AN OPERATING COIL AND A RESETTING COIL AND AT LEAST ONE SWITCHING CONTACT WHICH IS ACTUATED TO AN ACTIVE POSITION BY THE OPERATING COIL WHEN IT IS ENERGIZED AND IS ACTUATED TO ITS NORMAL POSITION BY THE RESETTING COIL WHEN IT IS ENERGIZED, SAID SWITCH DEVICE FURTHER COMPRISING RESILIENT MEANS FOR MAINTAINING SAID CONTACT IN SAID NORMAL POSITION WHEN ACTUATED THERETO UNTIL SAID OPERATINC OIL IS ENERGIZED AND LATCH MEANS FOR MAINTAINING SAID CONTACT IN SAID ACTIVE POSITION WHEN ACTUATED THERETO UNTIL SAID RESETTING COIL IS ENGERIGIZED, MEANS FOR CONTROLLING SAID OPERATING COIL AND SAID RESETTING COIL COMPRISING A UNIDIRECTIONAL POWER SUPPLY SOURCE, AND CONTROL CIRCUIT MEANS CONNECTING SAID SOURCE TO SAID OPERATING COIL AND SAID RESETTING COIL, SAID CONTROL CIRCUIT MEANS COMPRISING FIRST AND SECOND CONTROLLABLE SEMI-CONDUCTOR DEVICES FOR ALTERNATELY CONTROLLING THE RESPECTIVE RESETTING AND OPERATING COILS AND BEING RESPECTIVELY CONNECTED THEREACROSS, MEANS NORMALLY BIASING SAID FIRST SEMI-CONDUCTOR DEVICE TO NON-CONDUCTION THEREBY TO CAUSE ENERGIZATION OF SAID RESETTING COIL, MEANS 